Two thirds of London boroughs are failing to meet arrest targets set under the Met's stop and search guidance, police data shows.
It means that across the capital hundreds of thousands of people are being unnecessarily searched by the police — mostly black people, who are 11.5 times more likely to be stopped than their white counterparts.
In an effort to improve the reputation the tactic has, and to ensure it is "fair and effective", the force aims to achieve an arrest rate of 20% from stop and searches.
The Stop and Search Monitoring System Report shows that in November 2015, 13,227 stop and searches were carried out across London — 18.7% of which resulted in an arrest. Although this is an improvement on 2011, when just 8% produced arrests, it is still below the 20% target, with 20 of the 32 London boroughs failing to meet it.
Westminster has one of the highest rates of stop and search, yet one of the lowest arrest rates. Out of 799 stop and searches carried out in November 2015 just 13.3% resulted in arrests, meaning 561 people (86.7%) were released with no further action taken at the time.
In Tower Hamlets 652 people were searched, just 86 (13.3%) of whom were subsequently arrested. Conversely Richmond upon Thames had the lowest arrest rate at 11%. This is probably because only 91 people were pulled over by police.
While Sutton has the highest arrest rate at 25%, its stop and search rate is at the lower end with 175 people being stopped in November 2015, suggesting that some boroughs take a more targeted approach than others.
Lambeth has the highest search and stop rate. Out of 1,078 people stopped, 714 people (78%) were released with no further action taken at the time of arrest.
Among the boroughs with high stop and search rates, three also had high arrest rates: Lewisham (24.2%), Brent (23.5%) and Haringey (20.6%).
Joanne McCartney, chair of the London Assembly’s Police and Committee said of those not hitting the 20% target: "We would want to see those boroughs looked at by the Met to see how those rates can be improved. It is in the police's interests to improve arrest rates."
McCartney suggests that reasons for discrepancies between boroughs could be because "some boroughs have different operations for treating crime." There is also, she says, the issue of training; in local policing a third of officers have less than two years experience, so some officers may not be confident in carrying out stop and searches.
A Met spokesperson told Londonist "The [Met] does not set volume targets re. stop and search, meaning it does not tell officers they must do 10 or 20 searches per day for example.
"But it aims for 20% of all stop and searches to result in an arrest, and a minimum of 20% of all stops and searches to target weapons. In addition, 40% should target neighbourhood crimes."